The meteorological phenomena considered can comprise, especially, turbulence zones, icing zones, jet streams, as well as significant events such as volcanic eruptions or radioactive emissions.
It is known that a certain number of means are made available to the crew of an aircraft to provide information on the meteorological phenomena liable to have an impact on the flight along the envisaged flight plan. In particular, the following meteorological information sources used in the aeronautical domain are known: TEMSI charts, WINTEM charts, SIGMET messages, METAR messages, information from a meteorological radar, etc.
Although a set of means describing the atmospheric conditions which may have an effect on the flight are thus available to the crew of an aircraft, these means are separate and taken into account individually. Consequently, the crew themselves are compelled to summarize all the information provided to them. Moreover, such information is not necessarily correlated with the flight plan.
Thus, in particular, before a flight, the flight operations may provide the crew with a set of meteorological charts. Each meteorological chart presents a type of meteorological phenomenon or a group of meteorological phenomena over a very precise region of the Earth in a particular altitude layer. Moreover, each chart exhibits a temporal validity.
It is possible to estimate the number of charts received by a crew. This number corresponds to the number of types of chart, multiplied by the number of altitude layers, multiplied by the number of periods of validity of the prediction, multiplied by the number of prediction regions concerned in the flight, thus giving a very sizable number of charts.
The crew must then estimate, as a function of the flight plan followed (which defines a trajectory in space evolving in the course of time, that is to say a four-dimensional trajectory), the meteorological phenomena or the conditions of the atmosphere which will have an impact on the flight. They must thus search for a correlation between on the one hand the various charts and information with which they are provided, and on the other hand the flight plan. Such a task requires a good capacity for abstraction in four dimensions and for correlation of the various pieces of information.
In addition to possibly presenting a risk of erroneous interpretation, this customary procedure for processing and understanding the available information relating to the meteorological conditions liable to be encountered by an aircraft presents a considerable workload for the crew.